Torsion device for snowmobile skis



Aug. 25, 1970 H. A. HAGEN TORSION DEVICE FOR SNOWMOBILE SKIS Filed Feb.13, 1968 I VENTOR. W A. #46641 United States Patent 3,525,411 TORSIONDEVICE FOR SNOWMOBILE SKIS Harold A. Hagen, 101 Peavey Lane, Wayzata,Minn. 55391 Filed Feb. 13, 1968, Ser. No. 705,104 Int. Cl. B62b 17/04US. Cl. 180-5 3 Claims ABSTRACT OF THE DISCLOSURE A ground engaging skidevice for a snowmobile comprising an elongate ground engaging skiassembly including a leaf spring mounting member secured theretointermediate to ends thereof and closing confining a generallyrectangular shaped yieldable torsion member therein. An elongate skistandard adapted to be connected at its upper end to the conventionalsteering arm of the snowmobile to permit rotation of the standard aboutits longitudinal axis steering of the snowmobile. A generally invertedU- shaped engaging member secured to the lower end of the ski standardand embracing said mounting member and torsion member. A connectorelement on said torsion cooperatively engaged by a similar shapedconnector element on said engaging member whereby said standard andtorsion member are locked together to cause said ski standard and skiassembly to move as a unit when the standard is revolved about itslongitudinal axis but permitting forceable, yieldable movement of theski relative to the standard about a horizontal transverse axis.

SUMMARY OF INVENTION In conventional snowmobiles, the ground engagingski assembly is connected by an elongate standard to the steering arm ofthe snowmobile so that guiding of the snowmobile is accomplished byturning the skis about a vertical axis defined by the longitudinal axisof the standards. The ground-engaging skis must be capable of pivotingabout a horizontal transverse axis in order to traverse uneven terrainand in the conventional snowmobiles the ground engaging ski assembliesare connected to their associated standards for free limited pivotalmovement about a horizontal transverse axis. However, when thesnowmobile passes over an obstruction and becomes mo mentarily airborne,the ski assemblies tend to loosely tilt about their transverse axes andthe position of the ski cannot, therefore, be controlled by theoperator. Further, allowing the ground engaging skis to freely pivot byaction of gravity when the snowmobile becomes momentarily airborne,sometimes results in damage to the ski assemblies because the skis arenot properly positioned when reengaging the ground.

An object of the present invention is to overcome this problem whereinthe ski standards are uniquely connected to the ground engaging skiassemblies to permit steering of the ski assemblies but allowing the skiassemblies to be maintained in a predetermined relationship when thesnowmobile becomes momentarily airborne, yet also permitting forceable,yieldable movement of the ski assemblies about a substantiallyhorizontal transverse axis.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING FIG. 1 is a perspectiveview of a snowmobile incorporating my novel ski assembly,

FIG. 2 is an enlarged, exploded perspective view illustrating details ofconstruction of a novel invention,

FIG. 3 is a side elevational view of the lower end portion of the skistandard and the leaf springs of a ski assembly, and

3,525,411 Patented Aug. 25, 1970 ice DETAILED DESCRIPTION OF THEINVENTION Referring now to the drawings and most specifically to FIG. 1,it will be seen that a conventional snowmobile 10 is there shown andincorporates one embodiment of my invention. The snowmobile 10 includesa body 11 of conventional construction having an internal combustionengine mounted therein which drives ground engaging endless tracks 12 ina well known manner. Handle bars 13 are provided for steering thesnowmobile and these handle bars through suitable conventional steeringlinkage control the position of the ground-engaging ski assemblies 14,all of which is of well known construction. The ski assemblies 14 eachinclude an elongate generally arcuate shaped lower leaf spring 15, oneend being bent to form an eyelet 16 and the other end being arcuatelybent as at 17. The ski 14 has front and rear pairs of upwardlyprojecting cars 18 integrally formed therewith which are suitablyapertured and which are provided with pins 19 to secure the upper leafspring 15 thereto. An upper some what shorter spring 20 of generallyarcuate construction is positioned upon the leaf spring 15 and issecured thereto by suitable nut and bolt assemblies 21. The structuredefined hereinabove is of well known conventional construction and, perse, forms no part of the present invention.

The present invention is directed to the provision of a unique manner ofinterconnecting the ski standard with the leaf springs so that theassociated ski assembly will be maintained in a predetermined relationwhen airborne but will yieldably rock about a horizontal transverseaxis. This unique connection is also highly effective in facilitatingsteering of the ski assemblies. To this end, it will be noted that agenerally inverted U-shaped mounting member 22 is secured to the uppersurface of the upper leaf spring 20 intermediate the ends thereof. ThisU-shaped mounting member includes a web portion 23 having a pair of legs24 integrally formed therewith and extending downwardly therefrom, andterminating in a pair of apertured outturned flanges 25 through whichthe bolts of the bolt and nut assemblies 21 pass therethrough.

A generally rectangular shaped torsion member 26 formed of a yieldableresilient material, such as rubber or the like, is positioned andclosely confined within the volumetric space defined by the mountingmember 22 and the upper leaf spring 20. This torsion member which issnugly positioned within the confines of the mounting member has anopening therethrough and this opening 27 in the embodiment shown is ofhexagonal cross-sectional configuration. A first connector member 28which as shown is a hexagonal sleeve and is positioned in the hexagonalopening in snug fitting relation therewith. Referring now to FIG. 4, itwill be noted that the ends of hexagonal sleeve 28 are coplanar with thereduced ends of the torsion member 26.

The ski assembly also has an elongate ski standard 29 connected theretoand which is adapted to be connected at its upper end to the steeringarm of the sterring mechanism in a well known manner. The lower endportion of the standard 29 has a generally U-shaped engaging member 30integrally formed therewith and projecting downwardly therefrom. Thisengaging member 30 includes a web portion 31 having a pair of legs 32integrally formed therewith and depending therefrom each having ahexagonal opening 33 therein which are disposed in axial alignment.These openings 33 are of a smaller size than the outside diameter ordimensions of hexagonal connector sleeve 28.

The engaging member 30 is adapted to be positioned upon the mountingmember 22 so that the web portion 30 of the engaging member ispositioned upon and engages the web portion 23 of the mounting member.The legs 32 extend downwardly over the ends of the torsion member 26 sothat the ends of the hexagonal sleeve 28 bear against the inner surfacesof legs 32. A hexagonal connector member or sleeve 34 extends throughthe openings 33 in the legs 32 and through the hexagonal passage insleeve 28 in mating relation therewith. The connector sleeve 34 is of alength so that the ends thereof are substantially coplanar with theexterior surface of the legs 32.

An elongate headed bolt 35 which is threaded extends through the sleeve34 and is connected to the engaging member 30 by suitable nut 36.Washers 37 are positioned exteriorly of the legs 33 to provide aclamping surface thereat. With this arrangement, the engaging member 30is connected to a connector member or sleeve 38 by means of theconnector sleeve 34 and nut and bolt assembly so that the standard 29 isclamped to the sleeve 28. However, because of the yieldablecharacteristics of the torsion member 26, each ski assembly mayforceably yield or rock vertically about a horizontal transverse axiswhen traversing uneven terrain. However, when the snowmobile ismomentarily airborne when passing over a bump, the torsion member willretain the ski assembly in predetermined relation with respect to thestandard 29.

Another distinct advantage in the present arrangement is that thevarious components are interrelated in such a way as to facilitatesteering. In this regard, it will be noted that the legs 32 of theengaging member 30 bear against the legs 24 of the mounting member.Further, the ends of the web portion 23 of the mounting member alsobears against the legs 32 so that a substantially large metal bearingsurface is provided between the engaging member and mounting member.Therefore, when each standard is revolved about its longitudinal axis,this motion is transmitted to the ski by the coacting interengagingmetal surface areas of the mounting member and engaging member. Thisarrangement minimizes the occurrence of wear with respect to these partswhile the torsion member provides a connection between the standard andski assembly which serves to maintain the ski assembly in apredetermined relation when the ski assembly is airborne but allowsforceable rocking of the ski assembly.

It will, therefore, be seen from the foregoing description that I haveprovided a novel device for interconnecting the conventional skistandard to the ski assembly of a snowmobile which not only improves thesteering inexpensive construction but one which functions in a moreefiicient manner than any heretofore known comparable device.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the various partswithout departing from the scope of my invention.

What is claimed is:

1. A ski assembly for use with a snowmobile comprising a ground engagingski, a leaf spring secured to said ski and extending upwardly therefrom,an elongate generally vertically oriented standard adapted to beconnected at its upper end with the steering mechanism of thesnowmobile, a torsion member formed of yieldable resilient function butserves to maintain the ski assemblies in predetermined relation withrespect to the standard when the skis are airborne.

It will, therefore be seen from the foregoing description that my novelarrangement is not only of simple and material, and having an openingtherein, a generally U- shaped mounting member embracing said torsionune ber and being arranged to prevent rotary movement between saidmounting member and said torsion member, and mounting the same on saidspring, a generally U- shaped attachment member on the lower end of saidstandard engaging said mounting member, and having depending legsdisposed in close proximal relation with opposing sides of said mountingmember to provide with said mounting member coacting rigid bearingsurfaces whereby revolving movement of said standard about itslongitudinal axis causes turning of said ski, coupling elements on saidattachment member and on said torsion member extending into the openingand transmitting rotational movement between said torsion member andsaid attachment member whereby said torsion member yieldably retainssaid ski against vertical swinging movement relative to said standard.

2. The ski assembly as defined in claim 1 wherein said torsion member isof generally rectangular configuration.

3. The ski assembly as defined in claim 1 wherein one of said elementscomprises a sleeve.

References Cited UNITED STATES PATENTS 2,700,427 1/1955 Schomers 32,824,734 2/1958 Linn et al. 26757.1 3,006,627 10/ 1961 Paulsen.

3,041,656 7/1962 Goodall 267-57.l X 3,075,789 1/1963 Hott 2802953,119,131 1/1964 Yoder 9310 3,309,150 3/1967 Marier 1805 BENJAMIN HERSH,Primary Examiner L. J. PAPERNER, Assistant Examiner U.S. Cl. X.R.280-25, 26

